Improved photographic bath



UNITED STATES PATENT OFFICE;

ISAAC REI-IN, OF PHILADELPHIA, PENNSYLVANIA.

|MPRovED PHoTocRAPHlc BATH.

Specification forming part of Letters Patent No. l 3,885, dated December4, 1855.

To all whom it may concern,.-

Be it known that I, ISAAC REHN, of the city of Philadelphia, and Stateof Pennsylvania, have invented a new and useful Improvement in Baths forPhotographic Operations; and I do hereby declare that the following is afull and exact description of the same, reference being had to theaccompanying drawing, and to the gures marked thereon.

In photographic operations one of the greatest difficulties experiencedis in consequence of a film or scum arising to the surface of thesolutions in which are to be immersed the plates or paper, as the casemay be, and which scum, adhering to the surface of the plate, causes astain, which not only greatly impairs the perfection of the pictures,butin many instances entirely spoils them. To remove this scum manyefforts have been made, none of which have been successful, except bythe following method, which renders that part of the photographicprocess entirely successful and free from failure.

The nature of my invention is as follows: I construct a reservoir withone wall about one and a half inch higher than the other. Along thelowest side or wall is attached a conducting-trough, to which isattached a spout for the purpose of conducting the liquid into a properreceptacle. At the top and at one side of this reservoir I place areceiving-chamber into which is to be poured the solution for thefilling and overtiow of the reservoir. At the bottom of thisreceiving-chamber I make an opening communicating with the reservoir atthe Water-line of the same or such other point as may best effect thedesired object.

The operation of this bath is as follows:

The reservoir l, being filled with solution and supposing it to havebeen used, is covered with a film, as above mentioned. By pouring someadditional solution into the receiver 2 the current passes through theopening 3 into the reservoir l, causing the iiuid to ow over the lowerwall of the reservoir 1 into a conducting-trough 4, along which it iscarried to a proper receptacle, from which .it is to be again used, asbefore. The flow of the current over the wall of the reservoir into theconductingtrough carriesv'ith it all the scum or film that may be uponthe surface of the solution, leaving it entirely clean. By use thereservoir will get loose pieces of coating from the plates immersed init, which, from their greater specific gravity, sink to the bottom. Theuse of the receiving-chamberhere becomes more apparent, for while itsorifice is at the Water-surface of the reservoir the solution Inay bemade to overflow Without disturbing the sediment at the bottom of thereservoir. Upon immersing the plate into the solution, after havingoverflown the bath, another film is liberated; but the bulk of the platedisplaces a portion of solution, and by this displacement anotheroverflowis occasioned and the fresh film carried away also.

Having thus described my invention and the mode of its operation, what Iclaim, and desire to secure by Letters Patent, s-

The overflowing bath with the conductingtrough and receiving-chamber ortheir equivalents, as set forth.

ISAAC REI-IN.

Witnesses:

MARTIN ROBERTS, JAMES M. MOORE.

